Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old May 13th 05, 11:44 PM
Jim Cammarano
 
Posts: n/a
Default Balun = Power Loss?

Folks ---

Last night a ham mentioned that he was going to feed an antenna with 450 ohm
twin lead directly into his antenna tuner because the use of a balun would
result in less antenna gain 1db because of power loss. Comments?

73,

Jim kg6qhp


  #2   Report Post  
Old May 14th 05, 12:11 AM
 
Posts: n/a
Default

Yes, Your friend needs to read Roy's or Walt's stuff on baluns. W7EL
or W2DU. Need to find out why one needs a balun, and what it will do
for you.
73 Gary N4AST

  #3   Report Post  
Old May 14th 05, 12:15 AM
Roy Lewallen
 
Posts: n/a
Default

I think you should ask the person who made the comment.

It wouldn't be surprising if some 4:1 baluns have a loss of a dB or so
at some impedance levels. It's very unlikely that a 1:1 balun would have
this much loss. The questions a

1. Why does the person you quote think that the tuner will have less
loss when confronted by the different impedance than the balun had? It's
entirely possible that the tuner's loss will increase (or decrease) by a
dB or more when confronted by the different impedance presented when the
balun is removed. Has he done an analysis or made careful measurements
to confirm that he's actually reducing overall loss with the change?
2. Is the person you quote willing to accept the effects of common mode
current on his feedline which could result from removing the balun? (See
http://eznec.com/Amateur/Articles/Baluns.pdf.) One likely effect is that
the signal radiated in the desired direction will change due to feedline
radiation. Has he determined that he'll benefit from this by more than
one dB?
3. Does the person you quoted really think he'll be able to detect a 1
dB improvement?

Roy Lewallen, W7EL

Jim Cammarano wrote:
Folks ---

Last night a ham mentioned that he was going to feed an antenna with 450 ohm
twin lead directly into his antenna tuner because the use of a balun would
result in less antenna gain 1db because of power loss. Comments?

73,

Jim kg6qhp


  #4   Report Post  
Old May 14th 05, 12:02 AM
John Smith
 
Posts: n/a
Default

The tuner has no loss? I need one!!!

Warmest regards,
John
--
Marbles can be used in models with excellent results! However, if forced
to keep using all of mine up... I may end up at a disadvantage... I seem
to have misplaced some!!!


"Jim Cammarano" wrote in message
...
| Folks ---
|
| Last night a ham mentioned that he was going to feed an antenna with 450
ohm
| twin lead directly into his antenna tuner because the use of a balun would
| result in less antenna gain 1db because of power loss. Comments?
|
| 73,
|
| Jim kg6qhp
|
|


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Narrow lobe of a yagi [email protected] Antenna 43 March 29th 05 07:07 PM
Wanted: Power Supply for TR-4C KA9S-3_Jeff Homebrew 9 December 12th 04 11:55 PM
power output formula Ken Scharf Homebrew 62 October 11th 04 05:41 PM
hf output power loss Rescator Equipment 0 April 27th 04 09:30 PM
The two sorts of loss Reg Edwards Antenna 10 August 21st 03 07:41 PM


All times are GMT +1. The time now is 05:26 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017